Electric furnace for smelting ores.



A. E. BOOKWALTER.

ELECTRIC FURNACE FOR SMELTING ORES. I APPLICATION FILED APR.26. 1911.1,297,641. Patented Mar. 18,1919.

4 SHEETSSHEET 1.

Skier/mega A. E. BOOKWALTER. ELECTRIC FURNACE FOR SMELTING ORES.

APPLICATION FILED APR.26. I91].

Patented Mar. 18, 1919.

4 SHEETS-SHEET -2 A. E. BOOKWALTER.

ELECTRIC FURNACE FOR SMELTING ORES.

APPLICATION FILED APR 26 19l]. 1,297,641. Patented Mar. 18,1919.

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ELECTRIC FURNACE FOR SMELTING OR'ES.

. APPLICATION FILED APR.26. I91]. 1,297,641.

4 SHEETS'SHEET 4.

l 1Z0 6) 6% I 54- 1 Z@ 1-8 4 6 i 4? i a mvemfoz Patented Mar. 18, 1919.

UNITED STATES PATENT OFFICE.

ALBERT E. BOOKWALTER, 0F GOEUR DALENE, IDAHO.

ELECTRIC FURNACE FOB, SMELTING ORES.

To all whom it may concern:

Be it known that I, ALBERT E. BOOK- WALTER; a citizen of the UnitedStates, re.

' siding at Coeur dAlene, in the county of which it appertains to makeand use thesame.

This invention relates to a new and mproved process and apparatus forsmelting ores.

One object of the invention is to provide a process for smelting oreswhereby the ores are put through a calcining process in a furnace whichcauses them to be heated to almost the melting or fusing point, and thenmelting and fusing them by electric means, the current necessary toaccomplish this being considerably less than is required in furnacesheretofore known by reason of the heating during this calcining step.

Another obj ect of the invention is to provide a process and apparatusfor smelting ores in which there is practically no metal which is notrecovered from the crude ores. A further object of the invention is toprovide a dust chamber to be used in connection with the smeltingfurnace, said chamber being provided with suitable means for collectingthe dust carried from the furnace by the strong draft through the samein order that it may be again treated in the furnace.

Another object of the invention is to generally improve upon apparatusesof this character by the provision ofan eflicient and reliableconstruction, and one which will be well adaptedto the'purpose for whichit is designed.

With these and numerous other objects in view, the invention resides incertain details of construction, the combination and arrangement ofparts as will be hereinafter fully described and claimed.

In the accompanying drawings forming a part of the application, and inwhich simiparts lar reference characters designate like throughout theseveral views;

Figure 1 is a view, partly in elevation and partly in section, of thecomplete apparatus constructed in accordance with this invention forcarrying out the steps of the improved process; I.

Fig. 2 is a vertical sectional view of the smelting furnace taken on theplane of the line 22 of Fig.3;

Fig. 3 is a horizontal sectional view taken oFn' the plane indicatedbythe line 33 of Fig. is a verticalsectional view taken pin the planeindicated by the line H of Fig. 5 is a vertical sectional view of thedust chamber taken on the plane indicated by the line 55 of Fig. 6 andshowing the dust collecting means in front elevation;

, Fig. 6 is a vertical sectional view taken on the plane indicated bythe line 6-6 of Fig. 5; I

Fig. 7 is a detail sectional view through one of the horizontal waterpipes;

Fig. 8 is a horizontal sectional view of the dust chamber taken on theplane indicated by the line 8-8 of Fig. 6.

Referring more particularly to the drawings, and especially to Fig. 1,the letter A designates a smelting furnace in which the ores arecalcined and smelted, B the smoke pipe connected with the upper endof-the furnace for conveying the smoke and other products of combustionto a. chamber 0 provided with a dust collecting means, and D a settlingtank for separating the dust collected in the chamber C from the waterused in the collecting step of the process.

The furnace A- is somewhat similar to smelting furnaces now in use inthat it is. provided in its wall near its upper end with an opening 1through which it is charged. This opening 1 is closed when not in use bya door or cover 2 which is hung or suspended by means of suitable cablespassing over pulleys. However, it is to be understood that other meansthan this may be employed for closing the opening. The furnace A issubstantially square in cross section and is provided at its lower endwith a well 3 in which the molten metal collects and is drawn from thefurnace. As clearly shown by Fig. 3 of the drawings the well 3 extendssubstantially horizontally across the bottom of the furnace midwaybetween two opposite sides. The walls of the well 3 are substantiallyupright for a short distance, and then they are flared outwardly andupwardly on an incline to provide a hearth 3 for sup- Specification ofLetters Patent. 7 Patented Mar, 18, .1919,

Application filed April 26, 1917. Serial No. 164,778.

, porting the ore and for directing the molten metal 1nto the well.

Adjacent the well 3 and fixed in the walls of the furnace A in anysuitable manner are electrodes 4 and 5 composed preferably of acomposition of graphite, iron shavings or' filings and silica clay.These electrodes 4: and.5 are substantially rectangular in configurationin lan View and extend parallel with the well 3 on opposite sides of thesame. Conductors 6 and 7 connect the electrodes with a suitable'sourceof current in which is arranged a rheostat for controllin the same.

he furnace, A is preferably housed or in fact covered' by a suitableshed a having a flooring'b arranged substantially on a plane with thelower side of the charging open- Mounted upon the flooring b is a fanblower 8, and connected to the blower is a pair of bustle pipes 9 whichare disposed on opposite sides of the furnace A and extend at rightangles to the well 3, and are disposed in a plane slightly below theflooring 7). Connected to the lower side of each of the bustle pipes 9is aseries of vertically disposed pipes 10, the latter being arranged onthe exterior of the furnace A and having connected to their lower endstwyers 11. These twyersare all disposed in substantially the samehorizontal plane which is spaced slightly above the plane oftheelectrodes tand 5, and as clearly shown in. Fig. 2 of the drawings theyareprovided with removable and separable bushing members 12 to regulatethe air supplied to the furnace.

The well 3 is provided at one endwith a spout 13 whereby the moltenmetal may be drawn from the furnace. It is to be understood that thewell is slightly inclined from the spout 3 to cause. the metal to runfrom the latter when it is being drawn off.

At the other end of the well there is pro vided a slag spout 14 throughwhich the slag and other refuse material is removed from the furnace.

The pipe B heretofore mentioned is of arched formation. One, of. theends of this pipe is secured in a convenientmanner to the upper end orto .of the furnace A, while the other end of thepipe is mounted on orsecured to the top of the chamber C; Arranged upon the lower side ofthehorizontal portion or crown of the pipe B is a series of hoppers orpockets 15 which are capable of catching any mineral that may passthrough therein. The lower ends of these hoppersare provided withsuitable" closure members which may be operated to remove such mineraltherefrom.

The connection of the pipe B with thechamber C is at one end of thelatter. At the other end of the chamber is a vertical comthe pipe andwhich may, condense paratively high smoke pipe E. The ends of thechamber C below the pipes B and E are less in width than theintermediate portion ofthe chamber and communicate with thisintermediate portion ,by openings 6.

Disposed across the opening 6 adjacent the troughs 18, the lowermosttrough being disposed at the screen 16.

The numeral 19 represents a vertical water supply pipe to which areconnected a series of vertically spaced horizontally extending pipes" 20disposed on the side of the screen 16 adjacent the intermediate portionof the chamber C and arranged directlybeneath the troughs 18. ,The lowersidesof the pipes 20 are provided with a plurality of apertures oropenings 21 throughwhich water is sprayed upon the screen. An additionalspray pipe 22 bent into substantially semiextreme lower end of thecircular shape to conform to the shape of the upper portion .oftheopening 0 is also connected. to the supply pipe 19. The troughs l8communicate with a vertically disposed collecting pipe 23, the lower endof which is connected to-a ipe 24 which conveys the water and othermaterial to the settling tank D above briefly described.

This settling tank D may be of any suitable construction, and is hereshown as being provided with a pipe through which the water is drawn01f.

The ore to be smelted such as lead, silver or copper, is fed into thefurnace through the opening 1. After a certain amount of it has beenplaced therein, a layer of fuel such as wood or coke is placed upon theore. Another layer of ore is added, then another of fuel, and morelayers of first ore and then fuel are added until the furnace iscompletely filled. The blower 8 is then started and a strong draft ofair is thus sent through the material in the furnace from the lower endthereof.

will heat the ore to a drive off practically all of the volatile mattercontained therein. The temperature of the ore will practically reach themelting point of v the metal contained therein. By this time the ore,almost'in a molten state, will be disposed at the bottom of the furnaceand upon the hearth formed by the inclined edges of the wall of the well3. The current of electricity is then turnedon, and this current willpass from one of the electrodes 4 and 5 through the ore to the otherelectrode, the resistance of the ore being a considerable amount willcause it to "become The fuel being ignited considerable extent andheated and quickly melt. When melted, the

metal will run into the well 3 from which it is drawn by the s out 13.Other ore will drop down upon t e hearth and thus the smelting operationis comparatively a continuous one, it being understood that the furnaceis continuously charged. The slag and other refuse material is removedfrom The products of combustion and smoke pass vertically through thefurnace to the pipe B, and thence 'to the chamber C. Ow-

ing to the very strong draft created through the furnace a large amountof dust containing minerals will be blown through the pipe tal portionof the pipe B, and some of the gases will condense and fall into thesehop- B to the dust chamber. Some of this dust will collect in thehoppers 15 in the horizonpers. This material is removed from the hoppersand-again placed in the furnace to remove the valuable mineralstherefrom.

As smoke and other gases pass through the chamber C and 'up the smokestack E a great .amount of dust will be collected upon the screen 16'.This screen is continuously sprinkled with water from the pipes 20 and22 so that the dust is caused to collect in the troughs 18. The waterand dust will then be conveyed through the pipe 23 and pipe V2% to thetank D. Dust will settle to the bottom of this tank, and when aconsiderable quantity has been thus accumulated the water is allowed todrain off from the. tank and sediment is collected and pressed bricksand again fed to the furnace.

From the foregoing description it will be' seen that the ObJGCtS of theinvention have been effectively carried out as an improved and practicalfurnace for smelting ores has been provided. Practicallyall of the minera-ls contained in the ores are collected, and hence there is verylittle waste or refuse material. The cost of smelting ores is reduced bythe use of this'process, first by calcining the ores by heating themwith wood or coke, and then allowing the metals to be completely meltedorfused by the passage therethrough of an electric current when almostin a molten condition. A considerably less amount of current is requiredthan is required in the furnaces heretofore known for there the currentis passed through a comparatively cold ore.

As various changes in form, proportion and in the minor details ofconstruction may be resorted to without departing from the principle ofthis invention it is to be understood that I do not wish tobe limited tothe precise construction herein shown and de scribed.

I claim: "1

In a smelting. furnace, a furnace shell having a rectangular bottom anda polysided wall rising therefrom, said bottom having along its centralportion a relatively narrow well provided with a-molten metal outlet, apair of one piece electrodes extend ing from one side to the oppositeside of the furnace and lying on said bottom on opposite sides of andparallel to said well, said electrodes abutting the remaining twoopposite sides of said wall and being spaced from said well, said bottomof the furnace inclining downwardly from said electrodes to said welland forming means for supporting the ore to be melted by the electriccurrent passing between said electrodes.

In testimony whereof I have hereunto set my hand in the presence of twosubscribin witnesses.

ALBERT E. BOOKWALTER. Witnesses:

ELMEB C. RAUOH,

- W. J. BURNS.

